European investigators surveyed clinical labs on the topic of biomarker testing for heart failure (HF) and found that more labs are offering B-type natriuretic peptide (BNP), with N-terminal pro BNP (NT-proBNP) reigning as the preferred biomarker. Labs also support adjusted cutoff values for age and gender and for patients with renal insufficiency suspected of acute or chronic HF.

Findings of the CArdiac MARker Guidelines Uptake in Europe (CAMARGUE) Study appear in Clinica Chimica Acta.

The European Federation of Clinical Chemistry and Laboratory Medicine initiated this study to assess how closely biomarker testing for HF aligns with updated guidelines. Science has evolved significantly since the last survey in 2013, “so we were interested in seeing what the impact was of much more well-defined guidelines published in 2016, as well as the effect of greater clinician utilization of BNP and NT-proBNP measurements,” Paul Collinson, MD, a professor and honorary consultant cardiologist at St George’s University Hospitals NHS Foundation Trust in London, and a co-author of the study, told CLN Stat.

Survey participants received a web-based questionnaire that addressed various topics on HF testing, including assays used, analytical methods and manufacturers, reported measurement units, and decision thresholds for acute and chronic HF. Investigators also sought opinions on different thresholds in obesity or renal failure and quality assurance.

A cohort of 347 mostly European laboratories participated in the survey. Among these, 266 offered NP testing. Investigators determined that NP testing usage rose from 67% in 2013 to 77% in 2019. NT-proBNP continues to dominate in the market; 79% of labs reported using this assay. The market position of Roche diagnostics in Europe (the largest single supplier of NT-proBNP) partly explains this, Collinson said. However, “there is a much greater literature base for NT-proBNP as well as other practical advantages,” he added.

NT-proBNP is much more stable than BNP, he continued. Measuring this analyte in community settings offers significant sample handling advantages. “It helps that Roche licensed out NT-proBNP to other manufacturers so it is available on a range of platforms. Also, NT-proBNP, unlike BNP, is effectively standardized between platforms and manufacturers,” offered Collinson.

Investigators also reported that more labs had adopted guideline-recommended cutoffs, “although this was by no means universal,” noted Collinson. He and his co-authors reported that “recommended medical decision limits for acute HF were very well implemented for BNP (85%) and better focused for NT-proBNP (40%) than in the previous survey.”

The survey also revealed that 90% and 80% of laboratorians respectively would support translation of adjusted cutoff values for age and gender. Nearly two-thirds (63%) also supported a requirement for different cutoff values in patients with renal insufficiency who might have acute or chronic HF.

In other findings, 73% of respondents said they were accredited/certified, and 92% said they were conducting external quality assurance for NP assays, an increase from 84% in 2013.

The data indicate that the 2016 guidelines stimulated an uptick in labs offering NP testing and in adopting recommendations for best practices and in using adjusted medical decision limits. Future guidelines should encourage the use of more tailored cutoffs for confounding factors such as age and sex, noted the investigators. “It has been suggested that more tailored cutoffs to allow for specific populations such as renal failure, and that consideration should be given for age and sex specific cutoffs. This will require some further research, although there is a measure of literature already out there,” said Collinson.

A manuscript on troponin testing represents the study’s next phase, he added. “We hope to extend the audit in combination with other societies next time around to consider how best to encourage people to adopt evidence-based guidelines and focus much more on clinical application.”